1. Field of The Invention
The present invention relates to an electrical connector, and particularly to a card connector for connecting an electronic card to a printed circuit board in an electrical apparatus.
2. The Prior Art
Recently, a variety of card connectors have been developed to connect electronic cards to PCBs in different electrical apparatus thereby achieving different functions.
FIG. 4 shows a conventional card connector 5 with a card 6 inserted thereinto. The connector 5 consists of an upper housing member 51, a lower housing member 52 fixed to the upper housing member 51 and defining a slot 54 therebetween with an inlet 53. A number of contacts 55 are fixed to the lower housing member 52. The card 6 is inserted into the slot 54 via the inlet 53 to electrically connect with the contacts 55 whereby electrical signals can be transmitted from the card to a printed circuit board (not shown) on which the connector 5 is mounted.
The contacts 55 engage with the card 6 only by a spring force of the contacts 55 which is insufficient to ensure a firm engagement therebetween, resulting in a high contact resistance (CR) and, thus, an inferior signal transmission quality.
To overcome the disadvantage of the prior art, U.S. Pat. No. 5,000,694 discloses a card connector having a mechanism which ensures that the card firmly engages with the contacts. However, the mechanism disclosed in the '694 patent has a relatively complicated structure, resulting in a high cost of the connector.
Hence, an improved card connector is needed to eliminate the above mentioned defects of current card connectors.